SME DFM Tech Paper

1. MS899753
Design for Manufacturing
Related to Sheet Metal Parts
author
JON E. =F;Et;i( LE’SN. =.E.
.Ass;s~ant ?ciesscr
Rccnester ksthte of TecWcicsy
3xkes:er. %ew “0r<
abstract
conference
B!?ACTiCAL SHEET METAL PART DESiGi%
.Cc:cber 24-25. t 989
Trq. Michigan
index terms
Cesq
3:trensims
‘Aarxfaczn~~ Systefls
Sheer . Metal;
Soc:etv oi Manuiacrurlng Engineers l Sne .S,ME 3rwe l 3 3. -3cx szc
Dearborn. Mhtgan a81 21 l PClone (2: 3; 277 -: 502

2. S-WE TECH.VfC.4 L P-l PERS
This Techmcai ?ager may. nor be reprcauced :n ;chore or ;n part .n any
iorm inc!udmg .macnme-readaoie abstract. wtnout ?ermlsslon irom :he
Society oi Manuiacrurmg Enyneers. Bk ?ubiishq :hls paper. SME does
301 probtde an endorsement OI yoaucts or serwczzsw nlc.? may 5e discussed in
the paper’s zontexs.

9. DFM INCH/METRIC STC)CK
DFM GEOMETRIC DIMENSIONING AND TOLERANCING

10. DFM - OTHER CONSIDERATIONS

11. .‘*...b-,- c.-* ?-; ---> j--, 2

12. REFERENCES
i
BIBLIOGRAPHY

13. =ESIGN FOR MANUFACTURABILITY
* DESIGN EFFICIENCY
* --ADVANTAGES OF SHEET METAL
* INCH/METRIC SOURCING
* .GD&T
DESiGl< EFFICIEXCV
.-
.-
.-
-
BOOTHROYD,AXWHURST TECHNIQUE
.POLi TECHNIQUE
QUANTIFIED DESIGX EFFICIENCY
IDENTIFY PARTS TO ELIMINATE
CONCEPT STAGE TOOL
FORCES DESIGN h MANUFACTURiNG TO WORK
TOGETHER
SUCCSSSFULLY USED IN INDUSTRY

14. DESIGN EFFICIENCP
3 set x TMNP
D;E. - cut AssY TI.XE (secj
BASED ON:
1) ZANDLING TIHE
2! INSERTION TIME
3) THREE MAGIC QUESTIONS
WILL NOT HAVE 100% 3-h. GOAL
DESIGN-EZ'FICIENCY
THREE MAGIC QUESTIONS
1) DIFFERENT MOTION
2) DIFFERENT MATERIAL
3) ASSEMBLY (DISASSEHBLY)
REQUIREMENT

15. DESIGNXFPICIENCY
REDESIGN REQUIRES:
- CREATIVE TSiNRiNG
- VA/vE TECHNIQUES
- MULTIFUNCTIONAL TEAM
- END TO:
"WE HAVE TO DO IT..."
"THAT WON'T WORK"
"WE DON'T RAVE TIME"
"TEIE SYSTEM WON'" ALLOW..."
- REAL COST ACCOUNTING
ASSEMBLY COST
PART COST
TOOLING COST PER PART
.
-=-1----w--3 -- _ _T-p_Y. II - --. e~---n-- -- -- -----ea.___

16. RESULTS OF DFM
ELIMINATE 57% OF PARTS
REDUCE ASSEMBLY TIME BY 80%
INCREASE D.E. BY 4x
INCREASE RELIABIZJTY
DECREASE PRODUCT COST
INCREASE SERVICABILITY
REDUCE TIlME TO MARKET
FREE UP FL30R SPACE
DPH ADVANTAGES OF SHEET METAL
- COMBINE PARTS
- WROUGHT MATERIAL
- EXCELLENT TOLERANCE CONTROL
- PROTYPE /' SHORT RUN / PRODUCTION
- LENDS SELF TO "TRICKS"
EXAMPLES:
- KNEES IN ANGLES
- RIBS
- TWIST TABS
- SEMI 3ERFS
- LETTERING
- EXTRUDED HOLES
- ROLL PORXING
- PRECaATED
.

17. -.

18. ‘.!;;a -;t,- _
----d/-cd_ -3
DFM INCH/METRIC
EXAMPLE LOW CARBON STEEL
18 GUAGE - 1.214 mm
1.2 mm
-014
7- 014 ir 2 1% INCREASE
DPM INCH/METRIC
USE OF OVERLAPPING SIZES
OPEN TOLERANCE TO INCLUDE BOTH
INCH AND METRIC
METRIC
SIZE
EXN'IPLE: LOW CARBON STEELS
INCH
CONV
NEAREST
GAUGE
NOM
INCH
‘METRIC
COIUV
.8 mm .0315 21 * 0329 -836
1.2 mm .0472 18 -0478 1.214
1. 5ml -0591 16 -0598 1.519
1.6 mm -0630 15 -0673 1.709
2.3 am .0787 13 -0897 2.278
2.5 nun .0984 12 -1046 2.656

19. DFM INCH/METRIC
STEPS TO IMPLEMENT
0 PICK CLOSE SIZES AS STANDARD
.MATERIALS
0 SPECIFY METRIC WITH INCREASED
TOLERANCE ZONE THAT INCLUDES THE
SELECTED GUAGE
0 MAXE SUPPLIERS AWARE
0 MAKE DESIGNERS AWARE SO FUNCTION
IS NOT AFFECTED
-- FUNCTI3NAL CALLOUTS
- -1 0 TCLEZQNCZ SXDBACX BY 3ESI*GN
- MPG KNOWS NE3DED "OLEiMhCZ
- 3ATUMS
- SIMULATED .?UNCTIONAL MOUNTING !IX GENERALi
- SAME STAGING
- MANUFACTUZCNG
- QC
- ASSEMSLY
- XULZ'1KATICXAZ.a XGUAGE
- Y 14.5m - 1982
- XD-ST=-130f
- ISG - ETD

20. DPM / GDdT
DATUM A
- USE MORE TBAN THREE STAGING POINTS
IF ASSEHBLY HOUNTS ON SPECIFIC AREAS
- RESTEWIN TO SRADED -AREA IF THAT
SIMULATES USAGE
DATUHS3h C
- USE FUNCTIONAL
NON-FUNCTIONAL
- TCOLING BOLES
BOLES RATBER TBAN
EDGES
- PATTERN FEATURE
LOCAL -/a i- CALLCUT
DFH OTHER CDNSiDE,=TI9NS
-- DON 'T 'NELD AND GRi-NJ2 CORNERS
-- DESIGN TO REDUCE SCRAP'
- DESIGN TN0 -PARTS TOGETHER TO -REDUCE SCRAP
- ALLOW LOCAL DISTORTIDN AFTER BENDING/BlANXINC
-m NON- FUNCTX ONAL
- HOLES NEAR BEND
- TAFERED PLANGE -AND SEND
- HOLE NEAR EDGE
- EDGE BULGE DUE TO 3END
- CONSZDER SIZE OF 'i7ELDiNG EQUIPHENT
- CONSIDER SIZE OF ASSEHBLY EQUIPHENT
- mSTiCHED" ASSEMBLY
- NOTCS FOR TEAR SDNTROL AT BENDS

21. DPM -sx1- L T-As
CCOORRNNEERR BELIE? SO XATIBG
IART XESN'T REQUIRE
CRAMFPLERR -ANID3 IT IROVZXS
XX? ZONTROL 3R PREVEX-
"ION C? STRZSS CRACXIXG
ZASE OF
DFM CONCLUSION
DFM WORKS
SHEET METAL IS A KEY PROCESS TO
ACHIEVE DFM SAVINGS
DESIGN AND MANUFACTURING WORKING
TOGETHER CAN MAKE IT HAPEJEN